The Role of Ultrasound in Lower Extremity Wound Management

The role of imaging technologies in the diagnosis of hidradenitis suppurativa

Hidradenitis suppurativa is a chronic, inflammatory, recurrent, and debilitating disease of the hair follicle. It presents with painful, deep-seated, inflamed lesions, such as nodules, abscesses, sinus tracts, and fistulas, generally located in the main folds. Clinical severity assessment alone can be reductive; noninvasive skin imaging technologies, such as ultrasound, magnetic resonance imaging, medical infrared thermography, computed tomography, and positron emission tomography, provide subclinical anatomical and functional details. These instrumental techniques confirm the clinical suspect, thus allowing an earlier diagnosis and improving patients' clinical evaluation, staging, and management. Finally, they might be helpful for preoperative mapping. In this contribution, we provide an overview of the current knowledge about noninvasive skin imaging techniques with a particular focus on ultrasonography, which is widely used thanks to its precision, versatility, and availability.

The Application of Ultra-High-Frequency Ultrasound in Dermatology and Wound Management

The management of lower extremity wounds is frequently performed by means of clinical examination, representing a challenge for the clinician due to the various conditions that can potentially enter differential diagnosis. Several diagnostic techniques are available in the dermatologist’s arsenal as a support to diagnosis confirmation, including dermoscopy and ultrasonography. Recently, a novel ultrasonographic technique involving the use of ultra-high ultrasound frequencies has entered the scene, and appears a promising tool in the diagnostic workup of skin ulcerative lesions. The focus of this review is to discuss the potential role of ultra-high-frequency ultrasonography in the diagnostic workup of wounds in the light of the current applications of the technique.

Ultrasound Use in Diagnosis and Management of Venous Leg Ulcer

Leg ulcers caused by venous diseases are effectively assessed by Doppler ultrasonography. The examination provides clear anatomical and physiological information for the diagnosis, treatment planning, and real-time guiding during the surgical treatment. Diagnostic Doppler ultrasonography assesses deep, superficial, and perforator veins, starting from patency assessment by direct visualization and simply compression test. The internal flow can be assessed by pulse wave analysis, which is used for rule out downstream flow obstruction and valvular incompetence. The venous valve function of deep, superficial, and perforator systems can be evaluated by measuring the time of the retrograde flow after flow augmentation performing in the upright position. At the end of the study, the venous map will be obtained and this map will guide clinicians to target treatment where the culprit is. The ultrasound technology has made a big shift in the treatment in the venous disease. In recent years, after the evolution and wide availability of ultrasound, newer treatment modalities have emerged for venous treatment. These include endovenous thermal ablation, endovenous adhesive closure, and ultrasound-guided foam sclerotherapy. Patients no longer require general anesthesia or hospitalization. Therefore utilization of duplex ultrasound has also surged and played an essential role in both diagnosis and therapy in venous ulcer. This article has dedicated to reviewing basic anatomy, the technique in diagnosis, and treatment.

Therapeutic Ultrasound in Lower Extremity Wound Management

In medical practice, ultrasound (US) is used for diagnosis and therapy. High-frequency (1-4 MHz) and low-frequency (20-120 KHz) therapeutic US are relevant to wound healing. The heating effects of high-frequency US are important, whereas the mechanical effects of low-frequency US must be considered. The physiological effects of low-frequency US include metabolic enhancement, perfusion, wound cleansing, and the acceleration of wound granulation. The therapeutic efficacy of US depends on dose (W/cm2 time)and dosage (frequency of application, series). At adequate doses, high-frequency and low-frequency therapeutic US induce in vitro cell proliferation; protein synthesis; and the production of cytokines by fibroblasts, osteoblasts, and monocytes. The mechanical effects of low-frequency US cause transient cavitation in wound surfaces for soft and smooth wound cleaning, ulcer debridement, and the stimulation of granulation. These effects can be determined in clinical studies, though the quality of the studies done so far and of the evidence of the usefulness of US is poor. Nevertheless, high-frequency and low-frequency US may be reasonable options in the management of chronic wounds.

The Role of Hemodynamic Measurements in the Management of Venous and Ischemic Ulcers

There is a need for quantitative investigations in the vascular laboratory to manage lower extremity ulcers. The majority of leg ulcers are of venous (45%-60%) or arterial origin (10%-20%). Despite the increasing complexity of new devices used in vascular surgical practice, the anklebrachial pressure index (ABPI) remains the cornerstone for the differential diagnosis of ischemic ulcers. The toe-brachial pressure index and the pole test represent attractive alternative tests especially in patients with diabetes. Color flow Doppler imaging (CFDI) is advantageous over ABPI in cases in which wounds and ulcers prevent the use of a cuff by virtue of their size or location; additionally CFDI technology can detect nonflow limiting lesions, lesions to nonaxial arteries such as the deep femoral artery, or lesions limited to a single tibial artery. Continued improvements in the accuracy of CFDI have prompted some vascular surgeons to replace contrast arteriography in distal bypass procedures. Transcutaneous partial oxygen tension measurement (TcPO2) is another noninvasive method that is reliable to select the level of amputation and recommended to determine tissue viability in critically ischemic limbs and in the management of the diabetic foot. CFDI has revolutionized the diagnostic approach to venous disorders and it is considered the gold standard for the assessment of the venous system of the lower limb, causes minimal inconvenience to patients, and is easily repeatable, but it is considered highly operator dependent. Various plethysmography techniques are of limited application in ulcer investigations, because of their difficulty to calibrate signal, unless time measurements such as the postexercise refilling time are used.

Underrecognized Peripheral Arterial Disease in Patients With Diabetes Mellitus in Thailand: We Must Consider Neuroischemic Foot Ulcers From This Fallout

A range of prevalence of peripheral artery disease in diabetic patients has been estimated using the measurement of ankle brachial pressure index and clinical features in Asian countries. These data may be underestimates and hence underrecognized, raising questions about the numbers of patients with neuroischemic feet who are also at risk of diabetic foot ulcers. Underrecognition of these lesions may well increase the high levels of chronic wound burden resulting from peripheral artery disease as well as neuroischemic foot lesions. Improved education and training of clinical staff (nurses and family physicians) is required to combat these serious issues.

Emerging Evidence for Neuroischemic Diabetic Foot Ulcers: Model of Care and How to Adapt Practice

Although neuropathic ulceration remains the commonest type of foot ulcers among patients with diabetes, recent data suggest that ischemic (and therefore, neuroischemic) ulcers are on the rise. The high prevalence and incidence of diabetes and its attendant foot complications, coupled with the current trend where increasingly diabetes care is being provided by general practitioners (primary care physicians) would mean that primary care practices are expected to see greater numbers of diabetic foot ulcer patients. Unfortunately, these settings are frequently ill-equipped to appropriately manage diabetic foot ulcers either due to lack of adequately trained personnel and access to multidisciplinary foot care teams. Whereas neuropathic foot ulceration may appear to be less challenging, neuroischemic or ischemic ulcers portend a higher risk of adverse outcomes, including non-healing, infection, amputation, and death. The last 2 decades have witnessed a paradigm shift from neuropathy as the main etiological factor in diabetic foot disease to an ever-increasing preponderance of ischemic and/or neuroischemic ulceration. Available literature does not always consider the limited access primary care practices have to specialized multidisciplinary foot care teams. Additionally, in the case of neuroischemic and/or ischemic ulcers, existing guidelines on their diagnosis and management are varied and unclear. This review aimed at providing a simple understanding to the complex evidence base for diagnosing and treating neuroischemic and/or ischemic ulcers in a primary care setting. It emphasizes the need for urgent vascular review in all patients with ischemic/ neuroischemic ulcers and advocates effective participation of vascular specialists in diabetic foot clinics and combined ward rounds.